Stress in a hot place: Ecogenomics and phylogeography in a pantropical sentinel inhabiting multi-stressor volcanic soils

炎热地区的压力：居住在多压力源火山土壤中的泛热带哨兵的生态基因组学和系统发育地理学

基本信息

批准号：
NE/I026022/2
负责人：
Mark Hodson
金额：
$ 4.11万
依托单位：
University of York
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2012
资助国家：
英国
起止时间：
2012 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FI026022%2F2
关键词：
Stress hot place Ecogenomics phylogeography

项目摘要

Understanding of how any metazoan organism tolerates an extreme environment comprised of multiple stressors may help to predict the impacts of current and future multifaceted global change on biodiversity and ecological function. Active volcanic soils represent extreme environments with unique features: elevated metal-ion concentrations, constant degassing over a wide area, and high temperature. Elevated soil temperature, as well as low O2, high CO2, and acidified soil are inhospitable challenges to the resident biota. The present proposal will derive a mechanistic understanding of the adaptation of an ecologically-relevant, ecosytem engineering, soil-dwelling invasive earthworm species (Amynthas gracilis) to cocktails of physico-chemical stressors of natural origin. Furthermore, the observations on this metazoan life-form with extremophile traits will have applications in the bioeconomy (biotechnology, agriculture and vermicomposting), medicine (models for anoxia & hypercapnia), and environmental management (ecotoxicology, risk assessment, land reclamation). Furnas, a rural parish on São Miguel in the Azores, is situated inside a caldera of an active volcano. Persistent volcanic activity at Furnas creates a soil presenting three formidable life-threatening challenges: locally low O2 (10%) and high CO2 levels (54%), high temperatures (37oC), and elevated metal concentrations rendered bioavailable due to soil acidification (pH 5.8). It is astounding that this extreme soil supports a viable population of A. gracilis. [It is noteworthy that CO2 concentrations greater than 17% leads death within 1 minute in exposed humans.] The aim of this project is to investigate specific functional aspects of how this soil-dwelling multi-cellular animal tolerates the inhospitable conditions of active volcanic soils.We will investigate the molecular and physiological responses of populations of A. gracilis under three discrete scenarios:i) earthworms sampled directly from inactive and actively volcanic soils;ii) earthworms transplanted from volcanically active to microcosms located in non-active soils, and vice versa; and iii) a series of laboratory 'exposures' representing every combination of the three chemical/physical challenges encountered in the field (i.e. singular or combinatorial). Our observations will encompass the following: - Comprehensive soil analyses to allow modeling of metal availability for uptake by the earthworms. - Profiling gene expression to reveal how the earthworm regulates its transcriptome enabling it to tolerate the severe challenges presented by active volcanism. - Computational interrogation of genetic data to identify mutations in functionally significant target genes involved in metal stress, thermo-tolerance, CO2 metabolism, and hypoxia.- Measuring the expression level of a conserved gene known as "Hypoxia-Induced Factor" (HIF) which previous studies indicate is paramount in regulating responses to hypoxia, thermal stress, and metal toxicity in vertebrates.- Measuring the expression of genes belonging to the 'heat-shock' superfamily of stress-response chaperones.- Biochemical and physiological measurements to determine the efficiency of O2 transport across the body wall, and the amount and O2-affinity properties of the haemoglobin. - Measuring diurnal changes in the O2 consumption and ATP production rates of Amynthas to establish whether behavior and physiology are modified in active volcanic soils.In parallel, we propose to support a PhD student to determine the genetic structure of A. gracilis populations in the Azores, and (through collaboration) in Asia (Laos, Korea, Thailand, South China), the region of origin of the cosmopolitan species. The studentship will also study the organism's reproduction, reported to be predominately asexual (parthenogenetic), and the implications of this for a species that is a successful invasive colonizer across a wide circum-tropical range.

了解任何后生动物如何容忍由多种压力源组成的极端环境可能有助于预测当前和未来的多方面全球变化对生物多样性和生态功能的影响。活跃的火山土壤代表具有独特特征的极端环境：升高的金属离子浓度，在较大面积的恒定脱水和高温。土壤温度升高以及低O2，高二氧化碳和酸化的土壤对居民生物群而言是无聊的挑战。本提案将对与生态相关的，生态的工程，土壤侵入性worm物种（amyynthas gracilis）的适应性进行机械理解。此外，对这种带有极端性特征的后生动物生命形式的观察将在生物经济（生物技术，农业和ver骨化），医学（缺氧和超碳酸菌的模型）和环境管理（生态学，风险评估，土地再现）中应用。 Furnas是亚速尔群岛圣米格尔（SãoMiguel）的粗糙教区，位于活火山的火山口内。 Furnas的持续火山活动会产生三种可威胁生命的挑战的土壤：局部较低的O2（10％）和高二氧化碳水平（54％），高温（37oC）以及由于土壤酸化而导致的生物利用的金属浓度升高（pH 5.8）。令人震惊的是，这种极端的土壤支持可行的gracilis人群。 [值得注意的是，在暴露的人类中，二氧化碳浓度大于17％在1分钟内导致死亡。]该项目的目的是调查这种居住土壤的多个细胞动物如何容忍活性火山土壤的繁殖条件的特定功能方面土壤; ii）从火山活性到位于非活性土壤中的缩影移植的earth，反之亦然； iii）一系列实验室“暴露”，代表了该领域遇到的三种化学/物理挑战的每种组合（即单数或组合）。我们的观察结果将涵盖以下内容： - 综合土壤分析，允许对earth的摄取进行对金属的可用性进行建模。 - 分析基因表达，以揭示earth如何调节其转录组，从而使其能够耐受活跃火山主义带来的严重挑战。 - 对遗传数据的计算询问，以确定与金属应激，热耐受性，二氧化碳代谢和缺氧相关的功能重要靶基因突变。-测量称为“低氧诱导因子”（HIF）的保守基因的表达水平（HIF），以前的研究表明，确定对低氧，热胁迫和热质量的毒性的影响至关重要。压力反应伴侣的“热休克”。-生化和物理测量，以确定造血蛋白的O2运输效率，以及造血蛋白的数量和O2-亲和力的特性。-测量氮的消耗和ATP生产速率的昼夜昼夜变化，以建立较高的amynthas pravency why sovied of Pravisy warly sigity notifection notifection notifection notifection notifection notife in Rative in Coverie notifection是否有效地进行了劳动的劳动，是否有效地进行了行为劳动。博士生要确定亚速尔群岛曲霉种群的遗传结构，以及（通过合作）在亚洲（老挝，韩国，泰国，中国南部），这是国际化种类的起源地区。该学生还将研究该生物体的生殖，据报道是无性无性的（parttheneenenenenit），这对在广泛的环境热带范围内成功的侵入性菌落剂的含义。